Brazing of structural elements such as honeycomb and panel assemblies is normally carried out by coating with a brazing powder suspended in a binder or provided in the form of thin sheets or strips of brazing material on the opposed surfaces of the panel members of the honeycomb structure. When the honeycomb structure is sandwiched between the panel members and heat is applied, the brazing material will melt and flow into the joints defined between the honeycomb cells and their contact lines with the opposed panel surfaces.
A desirable characteristic or property of finished honeycomb panel assemblies is referred to as ductility or elongation. Normally certain structure materials can be elongated a certain percentage of their original unit length without harming the structural integrity. However, where the structure material takes the form of a honeycomb cell structure with brazed top and bottom panels, the elongation property is substantially impaired. In other words, only a very small percentage elongation of the material is possible before failure occurs. This characteristic of the honeycomb and brazed panel sheets thereto is believed a direct result of the particular methods and means employed at the present time to braze the various elements together. For example, with the use of large area coverage of brazing material on the surfaces of the opposed panels, there is an excess of brazing material which permanently remains on the opposing surfaces of the panels and thereby impairs the elongation characteristics of the panels themselves.
Further, as a consequence of present day techniques, more brazing material is used than is actually necessary to braze the specific joints involved in a honeycomb-panel configuration. The result is not only a waste but an increased expense and an increase in the overall weight of the panel itself. These disadvantages are cumulative with respect to the aforementioned problems associated with physical elongation.